[Elecraft] [K2] Problem with MH2 and K2/100

[jmalloy]

Hi, gang, I need your help.  I just received a new MH2 mike from 
Elecraft and intend it for eventual use on my third round K3 order.  In 
the meantime, I modified my K2 to use it -- the sheet included with the 
mike provided instructions for doing so and I added the resistor across 
pins 1 and 6 of the mike socket and use the header pins they provided. 
All went tickety-boo.  I used to use an old Icom hand mic which worked 
very well but I was looking forward to being all Elecraft (I have an 
Elecraft Hexkey, too!)

Well, darn if the thing is giving me trouble: it acts as if there's RF 
in the system but the mike socket is grounded and it even acts that way 
at low power; my watt meter shows approximately 40 watts of power when 
the mike key is depressed on LSB but -- get this -- no power is shown 
when it's on USB where it seems to work fine!

What should I check?  Help!

Thanks...

73,

Joe, W2RBA